System for controlling and operating technical processes

ABSTRACT

A system for operating and controlling technical processes having at least one component fashioned as a measuring instrument and a control device, which is connected by electrical lines to sensor and actuators of processes, and having a control program, a measurement and control unit, an operating and observation component, optionally a database, optionally a process printer and further components of a process automation, as appropriate, which are connected to one another via data channels and a control program.

BACKGROUND OF THE INVENTION

The invention relates to a system for operating and controllingtechnical processes. A large group of products, used chiefly forcontrolling machines, is generally known. They are known asstored-program controllers or programmable logic controllers (PLCs).These devices are equipped with governing control programs that have thetask of controlling machines and installations (processes) throughsensors and actuators. Visualization software independent of the controlsoftware is employed for operator guidance. Control software andvisualization do not fit together because they are different in concept,relate to different platforms, so that these approaches are notconsistent. This manifests itself in an inadequate adaptation to thedifferentiated requirements of the distinct processes. In practice, thisoften leads to problems and complicated approaches.

There is further known a group of products that are employed primarilyin research and development. They date back to the end of the 1980s,when PCs had attained a sufficient level of performance, chiefly ofgraphical capabilities. These are the so-called virtual measuringinstruments. Measuring instruments with knobs, buttons, switches andindicating instruments had been known up to that time. Measuringcircuits were physically constructed from wire and filters and the like.This was now replaced by virtual measuring instruments and measuringcircuits. Now there were images of such devices on the screen. Turningknobs and actuating buttons and switches was replaced by clicks of themouse. In this way a process could be operated and observed.

Automatic control, however, was not possible in this way. In order toremedy this defect, a programming language was superimposed thereover.In the opinion of many users, the institution of automation on the basisof such approaches is very complicated and demands a longfamiliarization time. Users need special knowledge, which they mustmaster. The effort is substantial. Consistency between operating andobserving and automation was not achieved with these approaches.Particularly in laboratory automation, it would be very advantageous ifthere were simple approaches making it possible to develop automationtasks quickly and without great effort, without the need for specialknowledge or the employment of specialists.

SUMMARY OF THE INVENTION

It is an object of the invention to remedy the before mentionedshortcomings. In order to effect the distinct tasks, a system isfurnished that integrates the various components of process automation,such as control program, process visualization, specification ofparameters and documentation, into a consistent system. The user isenabled to configure control sequences, so that there is no need ofprogramming and the learning of a programming language. The object ofthe invention is achieved in that the control program is linked via datachannels with the other components of the system, such as measuringinstruments and control devices, the operating and observationcomponent, and optionally further groups such as documentation anddatabases. Through the incorporation of the further components into thecontrol program, a great deal of flexibility is made possible, whichpermits optimal adaptation to the requirements of the automation of theprocesses in question.

The data exchange between the components is effected with standardtransmission protocols that allow the individual components either to berun on one device or to be distributed among various devices. Thedevices can then be subscribers of a standard data network, for exampleEthernet. In this way, applications can be conceived that permitadvantages in terms of effort and operational organization, because thedata network of an enterprise can also be utilized for the tasks ofautomating processes.

A further inventive concept is concerned with control sequences. First,the overall sequence of process control is split into control modules,these control modules being assigned to the sequences, events andfunctions categories, and these control modules being containers forprogram code. Three types of control modules result, namely, sequencemodules, event modules and function modules.

The sequence module, as the name expresses, is responsible for thetemporal sequencing of various activities. It takes over the processguidance. Process guidance means the control program of the processsequence. This will be explained for the example of a mixing process. Ina mixer, the process sequence results from controlling the charging ofthe species that are to be mixed, the heating of the mixing stockthrough temperature control, through rotation speed control of thestirrer and mixing time, emptying of the mixer, and cleaning.

The event module handles operations that affect process guidance and cantake place at a time that cannot be determined in advance. As soon asthe event takes place, activities are initiated that affect thesequence. For example, the event can be the attainment of a temperatureof a heating operation. A further example would be an operator actionvia the operating and observation component in which the operatorchanges the setpoint of a controller. Event modules can eithermomentarily interrupt the sequence and themselves take over processguidance during the interruption, or be executed in parallel with thesequences.

A characteristic of the function modules is that they take overactivities that run in parallel with other control modules. In thefilling of a vessel, for example, a plurality of species can be chargedat the same time, the filling operation of the individual species beingcontrolled by one function module each. Function modules are usuallyinvoked by sequence modules, less frequently by event modules. Typicalfurther operations that are executed by function modules are controlactions, heating operations, monitoring operations, etc. Functionmodules can acquire measurement data, which are depicted in the form oftrend curves on the operator interface. Function modules open upopportunities for optimizing the process sequence. Control programs canbe more fully and easily understood in terms of function modules.

One category of technical processes is referred to as batch processes ordiscontinuous processes. The characterizing feature of such processes isa start phase and an end phase (termination of the process). An examplewould be a pumping station, which is turned on as soon as a waterreservoir is to be filled. Starting operation and termination are to beassigned to the sequences category. For this reason, it is desirable toprovide a start module type and an end module type in the sequencescategory. This typization is not mandatory, because a sequence modulecould also control starting operation and termination.

As a consequence of this definition, the sequences category includes thethree module types, namely, start module, sequence module and endmodule. In the case of process sequences, critical states not providedfor in the normal operating sequence can occur. For example, suppose acontroller is malfunctioning so that a temperature exceeds a criticallimiting value. For safety reasons, it is then often necessary toterminate the process. This is referred to as emergency termination.According to the invention, therefore, a security module is defined. Thesecurity module reacts to events that do not happen in the normaloperating sequence. It is therefore assigned to the events category. Thesecurity module has the task of interrupting the normal process sequenceand terminating the process. As a consequence of this definition, theevents category includes the module types event module and securitymodule.

Distinct graphical symbols are assigned to the various module types.These graphical symbols are clearly distinguishable from one another. Inthe operating and observation component, which can contain a number ofscreens, module diagrams are provided. A user creates module diagrams inconfiguration mode. In this way, a very good overview of the processsequences is advantageously made possible. The control modules areplaced as graphical symbols in the module diagram and linked with lines.These lines show symbolically how control modules are invoked by othercontrol modules and can themselves invoke other control modules. Thearrangement of the symbols and the linking lines, which are subject toset rules, make it possible to identify at a glance the structure andthe sequences of the automation task. According to the invention, thecontrol modules whose program contents are currently being carried outare highlighted in runtime mode, that is, during the execution of aprocess. In this way an observer can identify in what stage the processsequence is.

The control modules are linked in accordance with set rules. Thesoftware checks whether the user is complying with these rules, so thaterrors are largely avoided. These rules state that control modules ofthe sequences category (sequence modules, start modules and end modules)are linked only vertically, that event modules and security modules arenot invoked by other control modules but can invoke other controlmodules, that function modules are linked horizontally with the invokingcontrol module.

It is important to note that the linking lines in the case of verticallyarranged control modules must also allow of a lateral offset, that thelinking lines in the case of horizontally linked function modules mustalso allow of an offset in the vertical direction, depending on how thecontrol modules are arranged in the module diagram. This becomesapparent from the images in the examples.

A user will desirably arrange the control modules from top to bottom ina manner corresponding to the program procedure. It is regarded asself-explanatory that the respective directions vertical and horizontalare interchangeable. The simple rules with which control modules areinvoked and invoke other modules, symbolized by the linking linesbetween modules, and the fact that the invention makes it possible toget by with only a very few distinct module types should be emphasized.The modules serve as virtual containers for program code. They areaccessed for example by double-clicking on the symbol of the controlmodule in the module diagram. An interface containing the program codeof the control program then opens, and the program code can now beedited.

The individual instructions of the control program contain keywordsserve as placeholders for further keywords and elements of program code.The keywords in the code of the control program, which are emphasized inclearly visible fashion, for example by underscoring and/or colorcoding, must necessarily be replaced by program code. Only when allkeywords have been replaced by program code is the control program ofthe control module released as finished.

According to one embodiment of the invention, the keywords permit accessto selection lists. By clicking on the keyword, the selection listassociated with the keyword is opened in simple fashion. The contents ofthe individual list items of the selection list in question areformulated such that they generate a meaningful and error-free programcode when they replace the keyword. It is therefore necessary that allkeywords must be replaced by a program code. Only when all keywords havebeen replaced by a program code is the control program of the controlmodule released as finished. Thus, if a list item is selected from theselection list, this list item automatically replaces the keyword.

Because of this way of creating program code, a user has no need tolearn the language. Aside from the values of constants, he writes noprogram text. The program text is automatically generated with the aidof the computer mouse; as a consequence, syntax errors are eliminated.Further, illogical or meaningless program sequences are eliminated,because the selection list as replacement for the keyword in questionmakes possible only meaningful and logical entries. This implies thaterror messages, such as are always necessary otherwise, do not happen.With the exception of an error message that appears if not all keywordshave been replaced.

All program instructions are assigned to the test or action categories.In this way, the first keyword of a program instruction is either Testor Action. A different word with the same meaning can also be chosen.Thus it is made very easy for the user to take a decision if he wishesto write a new line of the program. As soon as he inserts a new line,the Test and Action appear in the selection list. A click on one of thetwo selection items inserts either the Test or Action programinstruction. This contains further keywords, so that the programinstruction can be prepared with several steps of the same selectionprocedure.

Process states, operator actions, input parameters can be determinedwith the Test instruction. For example, it is possible to perform a testto determine whether a temperature has exceeded a certain value, whethera vessel is full, whether an article of equipment is turned on, whethera button has been actuated, and much else. The Test instruction has thestraightforward formulation >If (logical operation) then<. Options forthe Test instruction being possible in the form >If not then . . .<or >If for the first time then . . . <.

The Action instruction makes possible a wide variety of operations thatcan be assigned to the categories of process control, items ofinformation for operating personnel, storage of data (documentation),mathematical operations (formulas), programming operations (e.g., the“loop” example), output in reports.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are depicted in simplified formin the accompanying drawings, in which:

FIG. 1 shows a schematic arrangement of the components of processcontrol;

FIG. 2 shows symbols representing the three categories, namely, sequencemodules, event modules, function modules;

FIG. 3 shows an excerpt from a visualization diagram;

FIG. 4 a shows a module diagram;

FIG. 4 b shows a module diagram;

FIG. 5 shows a finished program code of a module; and

FIG. 6 a to FIG. 6 h show interactive creation of a program instruction.

DETAILED DESCRIPTION OF THE INVENTION

The reference characters in FIG. 1 have the following meanings:

-   -   1: a process to be controlled;    -   2: sensor and actuator lines, which link the sensors and        actuators of the process with the measurement and control units;    -   3: a measurement and control unit;    -   4: a control program;    -   5: an operating and observation component;    -   6: a database;    -   7: a printer for creating reports;    -   8: a data channel; and    -   9: data channels.

Process 1 of FIG. 1 is linked to a measurement and control unit 3 viameasurement and control lines 2. The measurement and control lines 2transport signals of the sensors of process 1 to a measurement andcontrol unit 3 and transport control signals in the reversed sense tothe actuators of process 1. The measurement and control unit 3 is both ameasuring instrument and a data-processing device. It makes certain thatthe process signals are transformed in such fashion that the data can beexchanged with a control program 4 via a data channel 8. The controlprogram 4 is linked to the other components of the system, that is theoperating and observation component 5, the database 6 and the printer 7(for creating reports) via data channels 9. Data transfer via the datachannels 8, 9 is effected with the Ethernet hardware protocol and theTCP/IP software protocol. As a result, the individual functions can beimplemented in one device or in distributed fashion over a plurality ofdevices. A high degree of flexibility is attained in adaptation to thespatial relationships in question and to the size of the application inquestion.

The control program 4 stands at the center of data transfer because itis linked in star fashion to other components 3, 5, 6 and 7 via datachannels 8, 9. As a result, the control program 4 can send data forobservation of the system, under program control, to the operating andobservation component 5, where process states are displayed to theoperator. Conversely, operator actions by the operator are supplied tothe control program 4, which in turn, on the basis of the instructions,initiate corresponding state changes in process 1. Also, the controlprogram 4 can exchange data with the database 6. On the one hand, it canread out process parameters, process them in the control the program,and control process 1 accordingly. Conversely, data for qualityvalidation can be passed on to the database 6. Report printer 7 willreceive data via one of data lines 9 and can then create reports.

Referring to FIG. 2, the reference characters have the followingmeanings:

-   -   10: the symbol of the start module of the sequences category;    -   11: the symbol of the sequence module of the sequences category;    -   12: the symbol of the end module of the sequences category;    -   13: the symbol of the event module of the events category; and    -   14: the symbol of the function module.

The symbols in FIG. 2 represent control modules. They can be put on theinterface in the module diagram, arranged and linked or joined withlines. In this way the framework of the control program can beconceived. A click on the module in question gives access to the programcode of the control program. The symbols show how they can be joined toother symbols. Sequence module 11 can be joined vertically to othersequence modules or to the start module and an end module. It can bejoined horizontally to function modules. Event module 13 can invoke onlya sequence module or an end module. It cannot, however, itself beinvoked by another module. Function module 14 can be invoked only by asequence module but cannot itself invoke another module.

The reference characters in FIG. 3 have the following meanings:

-   -   15, 16, 17: visualization objects of analog display devices; and    -   18, 19, 20: visualization objects of signal lights.

The three (virtual) analog display devices 15, 16, 17 of FIG. 3 show thetemperatures of three rooms designated as Room1, Room2 and Room3. The(virtual) signal lights indicate in which of rooms 15, 16, 17 thetemperature is currently being controlled in accordance with atemperature profile.

The reference characters in FIG. 4 a have the following meanings:

-   -   21: a start module;    -   21, 23, 24: sequence modules; and    -   25: an end module.

The reference characters in FIG. 4 b have the following meanings:

-   -   26: a start module;    -   27: a sequence module;    -   28: an end module; and    -   29, 30, 31: function modules.

The function according to FIG. 4 a and FIG. 4 b is next described inboth of the module diagrams shown in FIG. 4 a and FIG. 4 b, threeclimate-controlled rooms are represented by symbols 23, 24, 25 and 29,30, 31. The temperature is being controlled in the climate-controlledrooms. The salient difference is that in module diagram of FIG. 4 a onlyone room 23, 23, 24 can be controlled at a time, while in module diagramof FIG. 4 b the rooms can be controlled at the same time. The reason forthe difference is that control in FIG. 4 a is effected by sequencemodules 22, 23, 24, while in FIG. 4 b the control is brought about bythree function modules 29, 30, 31.

In using the sequence modules in FIG. 4 a, only one of these modules canfunction at a time, because the sequence module takes over processguidance. In FIG. 4 b, this task is entrusted to three function modules29, 30, 31. Function modules work in parallel and independently of oneanother. The rooms can thus be controlled at the same time. In FIG. 4 b,sequence module 27 takes over process guidance. Its only function is towait while the rooms are controlled by function modules 29, 30, 31.

FIG. 5 shows the finished program code of the sequence module 23 and ofthe function module 30. The temperature is first controlled at 45° C.during a defined time, then at 65° C., likewise during a fixed timeinterval. Afterward there is a regression to room temperature. Theindividual program instructions belong exclusively to the test andaction categories. The Test instruction is a block of instructions madeup of two lines in which Action instructions are commonly included. TheAction instruction in the second line turns on a digital channel(HeatingSystem1) of the connected process. Further Action instructionsand Test instructions correspond to the process. The Action instructionsin the third line from the top and in the next to last line correspondto the visualization object DisplayRoom2 (reference character 19 in FIG.3) and turn the signal lights on and off.

FIG. 6 a shows the finished Action instruction created interactively byclicking the mouse. The instruction causes the digital output of typeDigOut, with the name HeatingSystem1, to be set to an “on” status. FIG.6 b shows how the instruction is set up if a free line is not yetavailable. The mouse pointer is moved onto the line below the line to beinserted. Clicking the right mouse button causes the selection listTest/Action/Info to open as shown in FIG. 6 b. Action is selected.Referring to FIG. 6 c, clicking the left mouse button causes Set to beselected from the Action/Set selection list.

Referring to FIG. 6 d, the instruction still shows the underscoredkeywords Object and var. According to the rules, all keywords must bereplaced by program code. In the FIG. 6 e, the left mouse button isclicked on the keyword Object. The selection list opens as a result.Channel and Digital Output are selected. The instruction has theappearance shown in the FIG. 6 f, with the keywords ChannelName and varstill underscored.

Referring to FIG. 6 g clicking on the keyword ChannelName causes theavailable channels to be displayed. “HeathingSystem1” is selected. FIG.6 h shows that clicking on the keyword “var” causes “Heating System 1”to be replaced by H/L. Clicking on H/L causes the selection list to openas shown in the FIG. 6 h. “On” is selected and FIG. 6 i shows thefinished instruction, which was generated by a few clicks of the mouse.

1. A system for operating and controlling technical processes having atleast one component fashioned as a measuring instrument and controldevice, which is connected by electrical lines to sensors and actuatorsof processes, and having a control program, wherein a measurement andcontrol unit, an operating and observation component, optionally adatabase optionally a printer and further components of processautomation, as appropriate, are connected to one another by datachannels and a control program.
 2. The system for operating andcontrolling of claim 1 wherein data exchange via the data channelsbetween the components is effected with standard transmission protocols.3. The system for operating and controlling of claims 1 or 2 wherein thecontrol program is structured in control modules, the control modulesbeing assigned to the categories sequences, events and functions, andthese control modules being virtual containers for program code.
 4. Thesystem for operating and controlling of one of the foregoing claimswherein the sequence modules take over process guidance, so that theyare responsible for the control program of chronological sequencing ofthe various activities.
 5. The system for operating and controlling ofone of the foregoing claims wherein the event modules are initiated bydefined events that can take place in the process sequence and eithermomentarily interrupt the sequence and themselves take over processguidance during the interruption, or are executed in parallel with thesequences.
 6. The system for operating and controlling of one of theforegoing claims wherein the functions category includes the typefunction module and function modules perform tasks that are executed inparallel with sequences.
 7. The system for operating and controlling ofone of the foregoing claims wherein the sequences category contains themodule types sequence modules, start module and end modules.
 8. Thesystem for operating and controlling of one of the foregoing claimswherein the events category contains the module types event modules andsecurity modules, event modules initiated by events perform the assignedtasks, and security modules terminate processes in controlled fashion incase of extraordinary events.
 9. The system for operating andcontrolling of one of the foregoing claims wherein distinct graphicalsymbols are assigned as identification features to the module types and,in the module diagram, these symbols can be graphically joinedvertically and horizontally in accordance with set rules inconfiguration mode.
 10. The system for operating and controlling of oneof the foregoing claims wherein the linking lines between controlmodules symbolize invocations of the control modules.
 11. The system foroperating and controlling of one of the foregoing claims wherein, inruntime mode, the control modules whose program contents are currentlybeing carried out are highlighted.
 12. The system for operating andcontrolling of one of the foregoing claims wherein sequence modules,start module and end module are linked vertically.
 13. The system foroperating and controlling of one of the foregoing claims wherein eventmodules and security modules cannot be invoked by other control modulesbut can invoke other control modules.
 14. The system for operating andcontrolling of one of the foregoing claims wherein the invocation offunction modules is symbolized by horizontal lines.
 15. The system foroperating and controlling of one of the foregoing claims wherein thedirection of the horizontal and vertical arrangement can be interchangedwithout any change of function.
 16. The system for operating andcontrolling of one of the foregoing claims wherein the control modulesserve as virtual program containers and access to the program code isgained by virtual opening of program containers via keyboard or mouse.17. The system for operating and controlling of one of the foregoingclaims wherein the individual instructions of the control programinclude keywords, which serve as placeholders for further keywords andelements of program code.
 18. The system for operating and controllingof one of the foregoing claims wherein the keywords are coupled withassociated selection lists.
 19. The system for operating and controllingof one of the foregoing claims wherein the contents of the individualitems of the selection list in question are formulated such that, whenthey replace the keyword, they yield meaningful and error-free programcode.
 20. The system for operating and controlling of one of theforegoing claims wherein the selected keywords and elements of programcode replace the original keyword.
 21. The system for operating andcontrolling of one of the foregoing claims wherein the operation ofreplacing keywords is continued until all keywords have been replaced byfinished program code.
 22. The system for operating and controlling ofone of the foregoing claims wherein the program instructions areformulated such that they are assigned to the test or action categories.23. The system for operating and controlling of one of the foregoingclaims wherein the first keyword is a program test or actioninstruction.
 24. The system for operating and controlling of one of theforegoing claims wherein the test category contains the instruction withthe formulation having an illogical operation than meaning.